Microfabricated surgical device for interventional procedures

ABSTRACT

An actuator for an interventional surgical procedure is described. The actuator may include an actuator body having a distal end and a proximal end. A central expandable section is located between the distal end and the proximal end. The expandable section is operable between an unactuated condition in which the expandable section is in a furled state and an actuated condition in which the expandable section is in an unfurled state. A needle is located at the expandable section. The needle is moveable in an approximately perpendicular direction relative to a central longitudinal axis of the actuator body from a position within the actuator body to a position outside of the actuator body.

BACKGROUND

[0001] The present relates generally to surgical devices, and moreparticularly to microfabricated surgical devices for use incatheter-based interventional procedures.

[0002] Biological and surgical microelectromechanical systems (MEMS),useful for their ability to be placed into and easily maneuvered withina patient's body, are touted as the fastest growing area ofmicro-systems. For example, microcatheters are used in many medicalapplications for minimally invasive surgery. There are presently overone million surgical uses of catheters per year in the United States,representing a huge market

[0003] As surgeons continue to adopt and perform advanced surgicalprocedures, the miniaturization of medical devices is taking place,allowing surgery with small external incisions and catheter-basedmicrosurgical tools. With roots in laparoscopic surgery (entering theabdomen through the navel and small holes in the midsection), minimallyinvasive surgery can be performed by inserting catheters in the femoralartery at the base of a patient's thigh, navigating the blood vessels inthe patient's body, and arriving at problem areas like the heart orbrain. Once the distal tip of the catheter is precisely positionedinside the body, a microsurgical procedure like balloon angioplasty,stent placement, localized cauterization, or drug delivery can takeplace. With the reduced bodily reaction to microsurgery and theminimization of scar tissue, these procedures are highly preferred overmore typical “macro” surgeries.

SUMMARY

[0004] In one aspect, the invention features an actuator for aninterventional surgical procedure. The actuator comprises an actuatorbody having a distal end and a proximal end. A central expandablesection is located between the distal end and the proximal end. Theexpandable section is operable between an unactuated condition in whichthe expandable section is in a furled state and an actuated condition inwhich the expandable section is in unfurled state. A needle at theexpandable section is movable in an approximately perpendiculardirection relative to a central longitudinal axis of the actuator bodyfrom a position within the actuator body to a position outside of theactuator body when the expandable section is caused to change from thefurled state to the unfurled state.

[0005] Various implementations of the invention may include one or moreof the following features. The proximal end of the actuator body may bejoined to an end of a catheter. The distal end of the actuator body maybe joined to a tip end of the catheter. The expandable section includesan interior open area and a delivery conduit is used to supply anactivating fluid to the open area to cause the expandable section tochange from the furled state to the unfurled state. The expandablesection may be made from a polymer. The actuator may further include aretaining ring located at the distal end and at the proximal end of theactuator body. The needle may include a tip having an insertion edge orpoint. The tip may include an outlet port and a fluid pathway may beused to supply a therapeutic or diagnostic agent to the outlet port. Theneedle is a microfabricated needle, or it is a macroneedle.

[0006] In another aspect, the invention is directed to a microfabricatedsurgical device for an interventional surgical procedure. The deviceincludes a catheter having a distal end for insertion into andmanipulation within a body of a vascularized organism and a proximal endfor providing a user with control over the manipulation of the distalend of the catheter. An actuator is joined to the distal end of thecatheter. The actuator includes an actuator body and a needle joined toan expandable section of the actuator body such that the needle islocated within the actuator body when the actuator is in an unactuatedcondition and outside of the actuator body when the actuator is in anactuated condition. The needle is movable along a path substantiallyperpendicular to a central longitudinal axis of the actuator body whenthe actuator changes from the unactuated condition to the actuatedcondition. Fluid connections are provided at the distal end of thecatheter and a proximal end of the actuator to supply a therapeutic ordiagnostic agent to the needle, and to provide an activating fluid tothe actuator to cause the actuator to change from the unactuatedcondition to the actuated condition.

[0007] Various implementations of the invention may include one or moreof the following features. The catheter may be a therapeutic catheter.The expandable section may be in a furled state when the actuator is inthe unactuated condition and in an unfurled state when the actuator isin the actuated condition. The expandable section may be made from apolymer. The device may further include a retaining ring located atopposite ends of the actuator body. The expandable section may includean interior open area to which the activating fluid is supplied to causethe expandable section to change from the furled state to the unfurledstate. When the activating fluid is removed from the interior open area,the expandable section may return to the furled state.

[0008] In yet another aspect, the invention is directed to an actuatorfor an interventional surgical procedure comprising an actuator bodyhaving a distal end and a proximal end. A central expandable section islocated between the distal end and the proximal end. The expandablesection is operable between an unactuated condition in which theexpandable section is in a furled state and an actuated condition inwhich the expandable section is in an unfurled state. A plurality ofneedles are located at the expandable section. The needles are movablein an approximately perpendicular direction relative to a centrallongitudinal axis of the actuator body from a position within theactuator body to a position outside of the actuator body, when theexpandable section is caused to change from the furled state to theunfurled state.

[0009] Various implementations of the invention may include one or moreof the following features. The needles may be spaced along a length ofthe expandable section. The plurality of needles move at the same timewhen the expandable section changes from the furled state to theunfurled state. At least one of the plurality of needles may move beforeanother one of the plurality of needles when the expandable sectionchanges from the furled state to the unfurled state. Also, when theexpandable section changes from the furled state to the unfurled state,at least one of the plurality of needles may move in a direction that isdifferent from the direction of movement of another one of the pluralityof needles.

[0010] In still another aspect, the invention is directed to an actuatorfor an interventional surgical procedure comprising an actuator bodyhaving a distal end and a proximal end. An expandable section is locatedbetween the distal end and the proximal end. The expandable section isoperable between a furled state and an unfurled state. A needle islocated at the expandable section. The needle is movable from a positionwithin the actuator body to a position outside of the actuator body,when the expandable section is caused to change from the furled state tothe unfurled state.

[0011] An implementation of the invention may include a plurality ofneedles at the expandable section wherein when the expandable sectionchanges from the furled state to the unfurled state, at least one of theneedles moves in a direction that is different from the direction ofmovement of another one of the needles.

[0012] In yet another aspect, the invention is directed to an actuatorfor an interventional surgical procedure comprising an actuator bodyhaving a distal end and a proximal end. An expandable section is locatedbetween the distal end and the proximal end. The expandable section isoperable between a furled state and an unfurled state. The actuatorincludes means for causing the expandable section to change from thefurled state to the unfurled state. A needle is located at theexpandable section, and the needle is movable in an approximatelyperpendicular direction relative to a central longitudinal axis of theactuator body from a position within the actuator body to a positionoutside of the actuator body, when the expandable section is caused tochange from the furled state to the unfurled state.

[0013] An implementation of the invention may include means fordelivering a therapeutic or diagnostic agent to the needle.

[0014] Intraluminal injection catheters according to the presentinvention comprise a catheter body and a needle. The needle is disposedradially within a protected recess of the catheter body, typically neara distal end of the catheter body. By “disposed radially,” it is meantthat the needle lies in a generally tranverse direction perpendicular tothe axis of the catheter body at the point where the needle is located.In this way, as the needle is extended in a radial direction from theprotected recess, it will enter a luminal wall in a generally straight,radial direction which both maximizes the distance which the needle canpenetrate into the luminal wall and which minimizes tearing or damage tothe luminal tissue. In particular, the present prevention provides thatthe protected recess will have a depth which is greater than 60% of thewidth of the catheter body at the point where the needle is located, andfurther that the needle will have a length equal to at least 60% of thecatheter body width at the location where the needle is located.Usually, the catheter body width will be a diameter for catheter bodieshaving circular cross-sections, but could also be a major or minor axesin catheter bodies having ovoid cross-sections or other widths incatheter bodies having other cross-sectional geometries.

[0015] Usually, the protected recess will be disposed within anexpandable section of the catheter body, and the needle will be securedto an exterior surface of the expandable section. In that way, theneedle will be radially advanced when the expandable section is radiallyexpanded. In a presently preferred embodiment, the cross-section of theexpandable section is initially involuted, when the expandable sectionis furled, with a generally circular outside, a generally circularprotected recess, and an axial opening between the recess and theoutside. The needle will be attached to the exterior surface of thecatheter body within the protected recess at a location generally acrossfrom the axial opening so that the needle passes through the opening asthe expandable section is unfurled.

[0016] The catheter bodies will usually have a length in the range from50 cm to 250 cm, usually from 75 cm to 150 cm, with an outer diameter inthe range from 1 mm to 5 mm, usually from 1.5 mm to 3 mm. The expandablesection is typically expandable to maximum width in the range from 2 mmto 10 mm, usually from 3 mm to 8 mm. Typically, the expandable sectionwill be expanded by receiving a pressurized activating fluid.

[0017] The present invention further provides an intraluminal cathetercomprising a catheter body having a distal end, a proximal end, anexterior surface, and an expandable section located near the distal endand moveable between a furled configuration having a protected recessand an unfurled configuration. An effector, such as a needle, blade,sensor, electrode, or the like, is disposed on the exterior surface ofthe expandable section so that the effector is disposed within theprotected recess when the expandable section is furled. The effector isadvanced and usually filly exposed on the expandable section when theexpandable section is unfurled. Usually, the catheter body has agenerally circular exterior cross-section over at least most of itslength, and the expandable section will have a similar circular exteriorcross-section when furled. Other geometries as described above may alsobe used. The interior of the expandable section will typically beinvoluted when furled, preferably having a generally circular peripheralprotected recess and an axial opening between the outside and therecess. When the effector comprise a needle, the needle will usually beattached to the exterior surface within the protected recess at alocation generally across from the axial opening so that the needlepasses through the opening as the expandable section is unfurled. Thedimensions of the catheter body and nature of the expandable section aregenerally as described above with respect to the last embodiment.

[0018] An advantage of the invention is that it provides forhighly-localized therapeutic or diagnostic agent deployments withoutsignificant risk to patients. The invention is able to generate alocalized force that produces a microscale opening in the wall of anartery or vein without a significant axial motion component. Thissubstantially eliminates the risk of tears to vessel walls. Theinvention produces a minute and self-healing wound. The inventionpermits, among other interventional procedures, localized tumortreatments and the treatment of in sclerotic arteries.

[0019] The details of one or more embodiments of the invention are setforth in the accompanying drawings and the description below. Otherfeatures, objects and advantages of the invention will be apparent fromthe description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

[0020]FIG. 1A is a schematic, perspective view of a microfabricatedsurgical device for interventional procedures in an unactuatedcondition.

[0021]FIG. 1B is a schematic view along line 1B-1B of FIG. A.

[0022]FIG. 1C is a schematic view along line 1C-1C of FIG. 1A.

[0023]FIG. 2A is a schematic, perspective view of a microfabricatedsurgical device for interventional procedures in an actuated condition.

[0024]FIG. 2B is a schematic view along line 2B-2B of FIG. 2A.

[0025]FIG. 3 is a schematic, perspective view of the microfabricatedsurgical device of the present invention inserted into a patient'svasculature.

[0026]FIGS. 4A-4G are schematic, perspective views illustrating steps inthe fabrication of a microfabricated surgical device of the presentinvention.

[0027]FIG. 5 is a schematic, perspective view of another embodiment ofthe device of the present invention.

[0028]FIG. 6 is a schematic, perspective view of still anotherembodiment of the present invention, as inserted into a patient'svasculature.

[0029]FIGS. 7A and 7B are schematic views of other embodiments of thedevice of the present invention (in an unactuated condition) includingmultiple needles.

[0030]FIG. 8 is a schematic view of yet another embodiment of the deviceof the present invention (in an unactuated condition).

[0031] Like reference symbols and reference numbers in the variousdrawings indicate like elements.

DETAILED DESCRIPTION

[0032] The present invention is directed to microfabricated surgicaldevices and methods of using such devices in catheter-basedinterventional procedures. The present invention will be described interms of several representative embodiments and processes in fabricatinga microfabricated needle or microneedle, or even a macroneedle, for theinterventional delivery of therapeutic or diagnostic agents intovascular walls or perivascular tissue. (A vascular wall is the wall ofeither an artery or vein). Exemplary therapeutic agents include:inorganic pharmacological agents; organic pharmacological agents; cellswith special treatment functions including but not limited toundifferentiated, partially differentiated, or fully differentiatedsteam cells, islet cells, and genetically altered cells; micro-organismsincluding but not limited to viruses, bacteria, fungi, and parasites;organic genetic material including but not limited to genes,chromosomes, plasmids, DNA, RNA, mRNA, rRNA, tRNA, synthetic RNA,synthetic DNA, and combinations thereof; or any combination of the abovelisted agents. Exemplary diagnostic agents include: contrast mediums,radioactive makers, fluorescent makers, antibody makers, and enzymemakers.

[0033] The microneedle is inserted substantially normal to the wall of avessel (artery or vein) to eliminate as much trauma to the patient aspossible. Until the microneedle is at the site of an injection, it ispositioned out of the way so that it does not scrape against arterial orvenous walls with its tip. Specifically, the microneedle remainsenclosed in the walls of an actuator or sheath attached to a catheter sothat it will not injure the patient during intervention or the physicianduring handling. When the injection site is reached, movement of theactuator along the vessel terminated, and the actuator is operated tocause the microneedle to be thrust outwardly, substantiallyperpendicular to the central axis of a vessel, for instance, in whichthe catheter has been inserted As shown in FIGS. 1A-2B, amicrofabricated surgical device 10 includes an actuator 12 having anactuator body 12 a and a central longitudinal axis 12 b. The actuatorbody more or less forms a C-shaped outline having an opening or slit 12d extending substantially along its length. A microneedle 14 is locatedwithin the actuator body, as discussed in more detail below, when theactuator is in its unactuated condition (furled state) (FIG. 1B). Themicroneedle is moved outside the actuator body when the actuator isoperated to be in its actuated condition (unfurled state) (FIG. 2B).

[0034] The actuator may be capped at its proximal end 12 e and distalend 12 f by a lead end 16 and a tip end 18, respectively, of atherapeutic catheter 20. The catheter tip end serves as a means oflocating the actuator inside a blood vessel by use of a radio opaquecoatings or markers. The catheter tip also forms a seal at the distalend 12 f of the actuator. The lead end of the catheter provides thenecessary interconnects (fluidic, mechanical, electrical or optical) atthe proximal end 12 e of the actuator.

[0035] Retaining rings 22 a and 22 b are located at the distal andproximal ends, respectively, of the actuator. The catheter tip is joinedto the retaining ring 22 a, while the catheter lead is joined toretaining ring 22 b. The retaining rings are made of a thin, on theorder of 10 to 100 microns (μm), substantially rigid material, such asParylene (types C, D or N), or a metal, for example, aluminum, stainlesssteel, gold, titanium or tungsten. The retaining rings form a rigidsubstantially “C”—shaped structure at each end of the actuator. Thecatheter may be joined to the retaining rings by, for example, abutt-weld, an ultra-sonic weld, integral polymer encapsulation or anadhesive such as an epoxy.

[0036] The actuator body further comprises a central, expandable section24 located between retaining rings 22 a and 22 b. The expandable section24 includes an interior open area 26 for rapid expansion when anactivating fluid is supplied to that area. The central section 24 ismade of a thin, semi-rigid or rigid, expandable material, such as apolymer, for instance, Parylene (types C, D or N), silicone,polyurethane or polyimide. The central section 24, upon actuation, isexpandable somewhat like a balloon-device.

[0037] The central section is capable of withstanding pressures of up toabout 100 atmospheres upon application of the activating fluid to theopen area 26. The material from which the central section is made of isrigid or semi-rigid in that the central section returns substantially toits original configuration and orientation (the unactuated condition)when the activating fluid is removed from the open area 26. Thus, inthis sense, the central section is very much unlike a balloon which hasno inherently stable structure.

[0038] The open area 26 of the actuator is connected to a deliveryconduit, tube or fluid pathway 28 that extends from the catheter's leadend to the actuator's proximal end. The activating fluid is supplied tothe open area via the delivery tube. The delivery tube may beconstructed of Teflon® or other inert plastics. The activating fluid maybe a saline solution or a radio-opaque dye.

[0039] The microneedle 14 may be located approximately in the middle ofthe central section 24. However, as discussed below, this is notnecessary, especially when multiple microneedles are used. Themicroneedle is affixed to an exterior surface 24 a of the centralsection. The microneedle is affixed to the surface 24 a by an adhesive,such as cyanoacrylate. Alternatively, the microneedle may be joined tothe surface 24 a by a metallic or polymer mesh-like structure 30 (SeeFIG. 4F), which is itself affixed to the surface 24 a by an adhesive.The mesh-like structure may be made of, for instance, steel or nylon.

[0040] The microneedle includes a sharp tip 14 a and a shaft 14 b. Themicroneedle tip can provide an insertion edge or point. The shaft 14 bcan be hollow and the tip can have an outlet port 14 c, permitting theinjection of a pharmaceutical or drug into a patient. The microneedle,however, does not need to be hollow, as it maybe configured like aneural probe to accomplish other tasks.

[0041] As shown, the microneedle extends approximately perpendicularlyfrom surface 24 a. Thus, as described, the microneedle will movesubstantially perpendicularly to an axis of a vessel or artery intowhich has been inserted, to allow direct puncture or breach of vascularwalls.

[0042] The microneedle further includes a pharmaceutical or drug supplyconduit, tube or fluid pathway 14 d which places the microneedle influid communication with the appropriate fluid interconnect at thecatheter lead end. This supply tube may be formed integrally with theshaft 14 b, or it may be formed as a separate piece that is later joinedto the shaft by, for example, an adhesive such as an epoxy.

[0043] The needle 14 may be a 30-gauge, or smaller, steel needle.Alternatively, the microneedle may be microfabricated from polymers,other metals, metal alloys or semiconductor materials. The needle, forexample, may be made of Parylene, silicon or glass. Microneedles andmethods of fabrication are described in U.S. application Ser. No.09/877,653, filed Jun. 8, 2001, entitled “Microfabricated SurgicalDevice”, assigned to the assignee of the subject application, the entiredisclosure of which is incorporated herein by reference.

[0044] The catheter 20, in use, is inserted through an artery or veinand moved within a patient's vasculature, for instance, a vein 32, untila specific, targeted region 34 is reached (see FIG. 3). As is well knownin catheter-based interventional procedures, the catheter 20 may followa guide wire 36 that has previously been inserted into the patient.Optionally, the catheter 20 may also follow the path of apreviously-inserted guide catheter (not shown) that encompasses theguide wire. In either case, the actuator is hollow and has a low profileand fits over the guide wire.

[0045] During maneuvering of the catheter 20, well-known methods offluoroscopy or magnetic resonance imaging (MRI) can be used to image thecatheter and assist in positioning the actuator 12 and the microneedle14 at the target region. As the catheter is guided inside the patient'sbody, the microneedle remains unfurled or held inside the actuator bodyso that no trauma is caused to the vascular walls.

[0046] After being positioned at the target region 34, movement of thecatheter is terminated and the activating fluid is supplied to the openarea 26 of the actuator, causing the expandable section 24 to rapidlyunfurl, moving the microneedle 14 in a substantially perpendiculardirection, relative to the longitudinal central axis 12 b of theactuator body 12 a, to puncture a vascular wall 32 a. It may take onlybetween approximately 100 milliseconds and two seconds for themicroneedle to move from its furled state to its unfurled state.

[0047] The ends of the actuator at the retaining rings 22 a and 22 bremain rigidly fixed to the catheter 20. Thus, they do not deform duringactuation. Since the actuator begins as a furled structure, itsso-called pregnant shape exists as an unstable buckling mode. Thisinstability, upon actuation, produces a large scale motion of themicroneedle approximately perpendicular to the central axis of theactuator body, causing a rapid puncture of the vascular wall without alarge momentum transfer. As a result, a microscale opening is producedwith very minimal damage to the surrounding tissue. Also, since themomentum transfer is relatively small, only a negligible bias force isrequired to hold the catheter and actuator in place during actuation andpuncture.

[0048] The microneedle, in fact, travels so quickly and with such forcethat it can enter perivascular tissue 32 b as well as vascular tissue.Additionally, since the actuator is “parked” or stopped prior toactuation, more precise placement and control over penetration of thevascular wall are obtained.

[0049] After actuation of the microneedle and delivery of thepharmaceutical to the target region via the microneedle, the activatingfluid is exhausted from the open area 26 of the actuator, causing theexpandable section 24 to return to its original, furled state. This alsocauses the microneedle to be withdrawn from the vascular wall. Themicroneedle, being withdrawn, is once again sheathed by the actuator.

[0050] As shown in FIG. 4A, the fabrication of the actuator 12 may startwith a hollow tube or mandrel 36 that has a groove or slit 38 formedalong part of its length. The tube or mandrel functions as a mold. It iscoated with a dissolvable polymer that functions as a mold releasedevice as discussed below. The wall thickness of the tube will definethe cross-sectional dimension of the open area 26 of the actuator, andthe exterior cross-sectional dimension of the tube will determine theexterior cross-sectional dimension of the actuator. The length of thetube, obviously, also determines the overall length of the actuator.

[0051] The retaining rings 22 a and 22 b are next placed at the oppositeends, respectively, of the tube (FIG. 4B). Specifically, they are slidover the exterior surface of the tube or into the interior surface ofthe tube. The tube and the retaining rings are then coated with a thin,rigid or semi-rigid, expandable material 40, such as Parylene, silicone,polyurethane or polyimide.

[0052] For instance, a Parylene C polymer may be gas vapor depositedonto and into the mold. Parylene is the trade name for the polymerpoly-para-xylylene. Parylene C is the same monomer modified by thesubstitution of a chlorine atom for one of the aromatic hydrogens.Parylene C is used because of its conformality during deposition and itsrelatively high deposition rate, around 5 μm per hour.

[0053] The Parylene process is a conformal vapor deposition that takesplace at room temperature. A solid dimer is first vaporized at about150° C. and then cleaved into a monomer at about 650° C. This vaporizedmonomer is then brought into a room temperature deposition chamber, suchas one available from Specialty Coating Systems of Indianapolis, Ind.,where it condenses and polymerizes onto the mold. Because the mean freepath of the monomer gas molecules is on the order of 0.1 centimeter(cm), the Parylene deposition is very conformal. The Parylene coating ispinhole free at below a 25 nanometer (nm) thickness.

[0054] Due to the extreme conformality of the deposition process,Parylene will coat both the inside (via the slit 38) and outside of themold. The Parylene coating inside and outside the mold may be on theorder of 5 to 50 μm thick, and more typically about 25 μm thick.

[0055] Other Parylenes, such as Types N and D, may be used in place ofParylene C. The important thing is that the polymer be conformallydeposited. That is, the deposited polymer has a substantially constantthickness regardless of surface topologies or geometries.

[0056] Additionally, a fluid flood and air purge process could be usedto form a conformal polymer layer on and in the mold. Also, adip-coating process could be used to form a conformal polymer layer onand in the mold. Polymers that may be used in this process includepolyurethane, an epoxy or a silicone.

[0057] As shown in FIG. 4C, the next step is to release the actuatorstructure 12 from the mold or tube 36. This is accomplished by virtue ofthe mold release. Specifically, the dissolvable polymer that wasinitially coated onto the tube is dissolved in a solvent to release theactuator structure from the mold. The actuator structure is then openedfor placement of the microneedle 14 on the surface 24 a of theexpandable section 24 of the actuator (see FIG. 4D). Alternatively, ifthe expandable section 24 and the microneedle 14 are both made ofParylene, then the microneedle may be molded directly into surface 24 a.A technique for such direct molding is described in the above-identifiedapplication Ser. No. 09/877,653, which has been incorporated herein byreference. Also, at this point, a suitable opening or passageway may beformed at the proximal end of the actuator for establishing fluidcommunication between the open area 26 of the actuator and the deliveryconduit 28.

[0058] The microneedle is then placed in fluid communication with theproximal end of the actuator by means of, for instance, thepharmaceutical supply tube 14 d (FIG. 4E). The microneedle and supplytube may be joined together by a butt-weld, an ultra-sonic weld or anadhesive such as an epoxy. The microneedle 14 is then adhered to surface24 a by, for example, the metallic mesh-like structure 30 describedabove. (FIG. 4F).

[0059] Next, as shown in FIG. 4G, the retaining ring 22 b of theactuator is joined to the lead end of the catheter 20 by, for example,and as discussed, a butt-weld, an ultra sonic weld or an adhesive suchas an epoxy. The tip end of the catheter is joined to the retaining ring22 a in a similar fashion or during actuator fabrication. At this point,the appropriate fluid interconnects can be made between the lead end ofthe catheter, and the distal tip of the microneedle and the open area 26of the actuator.

[0060] Various microfabricated devices can be integrated into theneedle, actuator and catheter for metering flows, capturing samples ofbiological tissue, and measuring pH. The device 10, for instance, couldinclude electrical sensors for measuring the flow through themicroneedle as well as the pH of the pharmaceutical being deployed. Thedevice 10 could also include an intravascular ultrasonic sensor (IVUS)for locating vessel walls, and fiber optics, as is well known in theart, for viewing the target region. For such complete systems, highintegrity electrical, mechanical and fluid connections are provided totransfer power, energy, and pharmaceuticals or biological agents withreliability.

[0061] By way of example, the microneedle may have an overall length ofbetween about 200 and 3,000 microns (μm). The interior cross-sectionaldimension of the shaft 14 b and supply tube 14 d may be on the order of20 to 250 μm, while the tube's and shaft's exterior cross-sectionaldimension may be between about 100 and 500 μm. The overall length of theactuator body may be between about 5 and 50 millimeters (mm), while theexterior and interior cross-sectional dimensions of the actuator bodycan be between about 0.4 and 4 mm, and 0.5 and 5 mm, respectively. Thegap or slit through which the central section of the actuator unfurlsmay have a length of about 4-40 mm, and a cross-sectional dimension ofabout 50-500 μm. The diameter of the delivery tube for the activatingfluid may be about 100 μm. The catheter size may be between 1.5 and 15French (Fr).

[0062] Variations of the invention include a multiple-buckling actuatorwith a single supply tube for the activating fluid. Themultiple-buckling actuator includes multiple needles that can beinserted into or through a vessel wall for providing injection atdifferent locations or times.

[0063] For instance, as shown in FIG. 5, the actuator 120 includesmicroneedles 140 and 142 located at different points along a length orlongitudinal dimension of the central, expandable section 240. Theoperating pressure of the activating fluid is selected so that themicroneedles move at the same time. Alternatively, the pressure of theactivating fluid may be selected so that the microneedle 140 movesbefore the microneedle 142.

[0064] Specifically, the microneedle 140 is located at a portion of theexpandable section 240 (lower activation pressure) that, for the sameactivating fluid pressure, will buckle outwardly before that portion ofthe expandable section (higher activation pressure) where themicroneedle 142 is located. Thus, for example, if the operating pressureof the activating fluid within the open area of the expandable section240 is two pounds per square inch (psi), the microneedle 140 will movebefore the microneedle 142. It is only when the operating pressure isincreased to four psi, for instance, that the microneedle 142 will move.Thus, this mode of operation provides staged buckling with themicroneedle 140 moving at time t1 and pressure p1, and the microneedle142 moving at time t2 and p2, with t1 and p1 being less than t2 and p2,respectively.

[0065] This sort of staged buckling can also be provided with differentpneumatic or hydraulic connections at different parts of the centralsection 240 in which each part includes an individual microneedle.

[0066] Also, as shown in FIG. 6, an actuator 220 could be constructedsuch that its needles 222 and 224A move in different directions. Asshown, upon actuation, the needles move at angle of approximately 90° toeach other to puncture different parts of a vessel wall. A needle 224B(as shown in phantom) could alternatively be arranged to move at angleof about 180° to the needle 224A.

[0067] Moreover, as shown in FIG. 7A, in another embodiment, an actuator230 comprises actuator bodies 232 and 234 including needles 236 and 238,respectively, that move approximately horizontally at angle of about180° to each other. Also, as shown in FIG. 7B, an actuator 240 comprisesactuator bodies 242 and 244 including needles 242 and 244, respectively,that are configured to move at some angle relative to each other than90° or 180°. The central expandable section of the actuator 230 isprovided by central expandable sections 237 and 239 of the actuatorbodies 232 and 234, respectively. Similarly, the central expandablesection of the actuator 240 is provided by central expandable sections247 and 249 of the actuator bodies 242 and 244, respectively.

[0068] Additionally, as shown in FIG. 8, an actuator 250 may beconstructed that includes multiple needles 252 and 254 that move indifferent directions when the actuator is caused to change from theunactuated to the actuated condition. The needles 252 and 254, uponactivation, do not move in a substantially perpendicular directionrelative to the longitudinal axis of the actuator body 256.

[0069] Damage to the inside of arteries caused by abrasion or lesion canseriously affect patients with sometimes drastic consequences such asvasospasm, leading to arterial collapse and loss of blood flow. Breachof the arterial wall through interventional surgical needles can preventsuch problems.

[0070] The use of catheter-based interventional surgical microneedlesallows highly localized pharmaceutical injections without the limitationof injecting from outside the body. Common pharmaceutical procedurescarried out with intravascular injections cause unnecessary flushing ofthe drugs throughout the body and filtering through the kidneys, liverand the lymphatic system. On the other hand, localized injections allowslow, thorough integration of the drug into the tissue, thus performingthe task more efficiently and effectively, saving time, money, drugs,and lives.

[0071] A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.

What is claimed is:
 1. An actuator for an interventional surgicalprocedure comprising: an actuator body having a distal end and aproximal end; a central expandable section located between the distalend and the proximal end, said expandable section operable between anunactuated condition in which said expandable section is in a furledstate and an actuated condition in which said expandable section is inan unfurled state; and a needle at said expandable section, said needlebeing movable in an approximately perpendicular direction relative to acentral longitudinal axis of said actuator body from a position withinsaid actuator body to a position outside of said actuator body when saidexpandable section is caused to change from said furled state to saidunfurled state.
 2. The actuator of claim 1 wherein the proximal end isjoined to an end of a catheter.
 3. The actuator of claim 2 wherein thedistal end is joined to a tip end of the catheter.
 4. The actuator ofclaim 1 wherein said expandable section includes an interior open areaand further including a delivery conduit to supply an activating fluidto the open area to cause said expandable section to change from saidfurled state to said unfurled state.
 5. The actuator of claim 1 whereinsaid expandable section is made from a polymer.
 6. The actuator of claim1 further including a retaining ring located at the distal end and atthe proximal end.
 7. The actuator of claim 1 wherein the needle includesa tip having an insertion edge or point
 8. The actuator of claim 7wherein the tip includes an outlet port and further including a fluidpathway for supplying a therapeutic or diagnostic agent to the outletport.
 9. The actuator of claim 8 wherein the therapeutic agent isselected from the group consisting of: an inorganic pharmacologicalagent; an organic pharmacological agent; a cell with a treatmentfunction including an undifferentiated, partially differentiated, orfully differentiated stem cell, an islet, or a genetically altered cell;a micro-organism including a virus, a bacteria, a fungi, or a parasite;and an organic genetic material including a gene, a chromosome, aplasmid, DNA, RNA, mRNA, rRNA, tRNA, synthetic RNA, or synthetic DNA.10. The actuator of claim 8 wherein diagnostic agent is selected fromthe group consisting of: a contrast medium, a radioactive marker, afluorescent marker, an antibody marker, and an enzyme marker.
 11. Theactuator of claim 1 wherein the needle is a microfabricated needle. 12.The actuator of claim 1 wherein the needle is a macroneedle.
 13. Amicrofabricated surgical device for an interventional surgical procedurecomprising: a catheter having a distal end for insertion into andmanipulation within a body of a vascularized organism and a proximal endfor providing a user with control over the manipulation of the distalend of the catheter within the body; an actuator joined to the distalend of the catheter, said actuator including an actuator body and aneedle joined to an expandable section of the actuator body such thatsaid needle is located within said actuator body when said actuator isin an unactuated condition and outside of said actuator body when saidactuator is in an actuated condition, said needle being movable along apath substantially perpendicular to a central longitudinal axis of saidactuator body when said actuator changes from the unactuated conditionto the actuated condition; and fluid connections at the distal end ofthe catheter and a proximal end of said actuator to supply a therapeuticor diagnostic agent to said needle, and to provide an activating fluidto said actuator to cause:said actuator to change from the unactuatedcondition to the actuated condition,.
 14. The device of claim 13 whereinthe catheter is a therapeutic catheter.
 15. The device of claim 13wherein said expandable section is in a furled state when the actuatoris in the unactuated condition and in an unfurled state when theactuator is in the actuated condition.
 16. The device of claim 15wherein said expandable section includes an interior open area to whichthe activating fluid is supplied to cause said expandable section tochange from the furled state to the unfurled state.
 17. The device ofclaim 16 wherein when the activating fluid is removed from the interioropen area, said expandable section returns to the furled state.
 18. Thedevice of claim 13 wherein said expandable section is made from apolymer.
 19. The device of claim 13 further including a retaining ringlocated at opposite ends of the actuator body.
 20. An actuator for aninterventional surgical procedure comprising: an actuator body having adistal end and a proximal end; a central expandable section locatedbetween the distal end and the proximal end, said expandable sectionoperable between an unactuated condition in which said expandablesection is in a furled state and an actuated condition in which saidexpandable section is in an unfurled state; and a plurality needles atsaid expandable section, said needles being movable in an approximatelyperpendicular direction relative to a central longitudinal axis of saidactuator body from a position within said actuator body to a positionoutside of said actuator body, when said expandable section is caused tochange from said furled state to said unfurled state.
 21. The actuatorof claim 20 wherein said needles are spaced along a length of saidexpandable section.
 22. The actuator of claim 21 wherein when saidexpandable section changes from the furled state to the unfurled state,the plurality of needles move at the same time.
 23. The actuator ofclaim 21 wherein when said expandable section changes from the furledstate to the unfurled state, at least one of the plurality of needlesmoves before another one of the plurality of needles.
 24. The actuatorof claim 20 wherein when said expandable section changes from the furledstate to the unfurled state, at least one of the plurality of needlesmoves in a direction that is different from the direction of movement ofanother one of the plurality of needles.
 25. An actuator for aninterventional surgical procedure comprising: an actuator body having adistal end and a proximal end; an expandable section located between thedistal end and the proximal end, said expandable section operablebetween a furled state and an unfurled state; and a needle at saidexpandable section, said needle being movable from a position withinsaid actuator body to a position outside of said actuator body, whensaid expandable section is caused to change from said furled state tosaid unfurled state.
 26. The actuator of claim 25 further including aplurality of needles at said expandable section wherein when saidexpandable section changes from the furled state to the unfurled state,at least one of the needles moves in a direction that is different fromthe direction of movement of another one of the needles.
 27. An actuatorfor an interventional surgical procedure comprising: an actuator bodyhaving a distal end and a proximal end; an expandable section locatedbetween the distal end and the proximal end, said expandable sectionoperable between a furled state and an unfurled state; means for causingsaid expandable section to change from said furled state to saidunfurled state; and a needle at said expandable section, said needlebeing movable in an approximately perpendicular direction relative to acentral longitudinal axis of said actuator body from a position withinsaid actuator body to a position outside of said actuator body when saidexpandable section is caused to change from said furled state tounfurled state.
 28. The actuator of claim 27 further including means fordelivering a therapeutic or diagnostic agents to said needle.
 29. Anintraluminal injection catheter comprising: a catheter body having adistal end, a proximal end, and a protected recess having a depthgreater than 60% of the width of the catheter body; and a needledisposed radially within the protected recess, said needle having alength equal to at least 60% of the width of the catheter body; whereinthe needle is fully extendable in a radial direction from the protectedrecess to penetrate a luminal wall when the catheter is in a body lumen.30. An intraluminal injection catheter as in claim 29, wherein theprotected recess is disposed within an expandable section of thecatheter body.
 31. An intraluminal injection catheter as in claim 30,wherein the needle is secured to an exterior surface of the expandablesection of the catheter body so that the needle is radially advancedwhen the expandable section is radially expanded.
 32. An intraluminalinjection catheter as in claim 31, wherein the catheter body has agenerally circular exterior cross-section and wherein the expandablesection has a generally circular exterior cross-section when furled. 33.An intraluminal injection catheter as in claim 32, wherein thecross-section of the expandable section is involuted when furled with agenerally circular outside, a generally circular protected recess, andan axial opening between the outside and the recess.
 34. An intraluminalinjection catheter as in claim 33, wherein the needle is attached to theexterior surface within the protected recess at a location generallyacross from the axial opening so that the needle passes through theopening as the expandable section is unfurled.
 35. An intraluminalinjection as in claim 31, wherein the catheter body has a length in therange from 50 cm to 250 cm and an outer diameter in the range from 1 mmto 5 mm, wherein the expandable section is expandable to a maximum widthin the range from 2 mm to 10 mm.
 36. An intraluminal injection catheteras in claim 31, wherein the expandable section of the catheter body hasan interior open area adapted to receive a pressurized activating fluidto expand the expandable section.
 37. An intraluminal cathetercomprising: a catheter body having a distal end, a proximal end, anexterior surface, and an expandable section located near the distal endand movable between a furled configuration having a protected recess andan unfurled configuration; and an effector disposed on the exteriorsurface of the expandable section so that the effector is within theprotected recess when the expandable section is furled and the effectoris fully exposed on the expandable section when the expandable sectionis unfurled.
 38. An intraluminal catheter as in claim 37, wherein thecatheter body has a generally circular exterior cross-section andwherein the expandable section has a generally circular exteriorcross-section when furled.
 39. An intraluminal catheter as in claim 38,wherein the cross-section of the expandable section is involuted whenfurled with a generally circular outside, a generally circular protectedrecess, and an axial opening between the outside and the recess.
 40. Anintraluminal catheter as in claim 39, wherein the effector comprises aneedle attached to the exterior surface within the protected recess at alocation generally across from the axial opening so that the needlepasses through the opening as the expandable section is unfurled.
 41. Anintraluminal catheter as in claim 37, wherein the catheter body has alength in the range from 50 cm to 250 cm and an outer diameter in therange from 1 mm to 5 mm, wherein the expandable section is expandable toa maximum width in the range from 2 mm to 10 mm.
 42. An intraluminalcatheter as in claim 37, wherein the expandable section of the catheterbody has an interior open area adapted to receive a pressurizedactivating fluid to expand the expandable section.